The complete disintegration of nuclear envelope in a cell cycle marks the
a)	Start of prophase of mitosis	b)	Start of metaphase of mitosis
c)	End of anaphase of mitosis	d)	Start of telophase of mitosis

(b)

The complete disintegration of the nuclear envelope marks the start of the second phase of mitosis, i.e., metaphase. Hence the chromosomes are spread through the cytoplasm of the cell. By this stage, condensation of chromosomes is completed and they can be observed clearly under the microscope. This then, is the stage of which morphology of chromosomes is most easily studied. At this stage, metaphase chromosomes are made up of two sister chromatids, which are held together by the centromere